Polymeric composites that contain organic and/or inorganic filler materials have become desirable for a variety of uses because of their excellent mechanical properties and weathering stability. Foamed versions of these materials can have a relatively low density yet the filler materials can provide a composite material that is extremely strong. The polymer provided in the composite can help provide good toughness (i.e., resistance to brittle fracture) and resistance to degradation from weathering to the composite when it is exposed to the environment. Thus, polymeric composites including organic and/or inorganic fillers can be used in a variety of applications.
The use of polyurethane composites has grown over the last three decades. This can be attributed to their superior tensile strength, impact resistance, and abrasion resistance compared to, for example, unsaturated polyester and vinyl ester-based composites. One of the methods to manufacture high-performance highly-filled polyurethane composite products is to increase the content of reinforcement, such as inorganic fibers, in such products. However, when the reinforcing inorganic fiber content is increased, the viscosity of the starting composite mixture also increases making processing into products more difficult. In addition, when a large amount of reinforcing inorganic fiber is used, more fibers can break and crush during the manufacturing process because of their brittle nature, resulting in a decrease in the reinforcing effect of fibers. Thus, there is a need for alternate reinforcing materials in polyurethane composites. The compositions and methods described herein address these and other needs.